Controllable All-Optical Chaotic Logic Operation And Real-time Chaotic Radar Ranging

Vertical cavity surface emitting laser(VCSEL),as one of micro lasers,has many advantages,such aslow manufacturing cost,low threshold current,compact structure,circular output beam profile and wafer scale integration.The VCSEL with optical injection or optical feedback,as a chaotic light source,can easily produce the chaotic signal with large bandwidth and high-dimension,and has a strong anti-jamming capability.Therefore,it has been generalized to apply in the generation of high rate random number,chaotic optical sensing,optical chaotic logic gate,chaotic secure communication,chaotic radar ranging and so on.When the chaotic system of the VCSEL with optical injection is applied in optical chaotic logic operation and chaotic radar ranging,some key technologies and physical mechanisms need to be solved urgently.Motivated by these problems,in this project we have done some innovative research works,their main contents are given as follows.(1)Based on the polarization switching mechanism in an optically injected VCSEL,and the new electro-optic modulation theory.The two linear-polarization(LP)lights of the laser are considered as two logic outputs.Under the electro-optic modulation,one of the logic outputs achieved the NOT operation with the other one.With thesame logic input signal,we perform various digital signal processing(AND,OR,XNOR,NAND,NOR and XOR)in the optical domain,by controlling the logic operations of the applied electricfield between the two logic input signals.On this basis,the logic operation of half-adder isfurther implemented.This work is completed in chapter 3.(2)Using the dynamical properties of the polarization bistability that depends on the detunning of the injected light,we implement reliable all-optical stochastic logic gates in the cascaded VCSELs with optical-injection.Here,two logic inputs are encoded in the detuning of the injected light from a tunable CW laser.The logic outputs are decoded from the two orthogonal polarization lights emitted from the optically injected VCSELs.For the same logic inputs,under electro-optic modulation,we perform various digital signal processing(NOT,AND,NAND,XOR,XNOR,OR,NOR)in the all-optical domain by controlling the logic operation of the applied electric field.Also we explore their delay storages by using the mechanism of the generalized chaotic synchronization.To quantify the reliabilities of these logic gates,we further demonstrate their success probabilities.The related work can be found in chapter 4.(3)According to the complete chaos synchronization and the Hilbert phase trans--formation principle,we propose a novel real-time multi-target ranging scheme for chaotic lidar based on the chaos synchronization system of the drive-response VCSELs.In this scheme,using the linear electro-optical effect of the periodically polarized LiNbO3 crystal(PPLN)to electro-optically modulate the x and y polarization components of the laser at the driving and responding portions,respectively,to stabilize the two polarization components in the chaotic synchronization state.We also discuss the range of key parameters of the system,such as bias current,applied electric field and channel delay,when the two polarization components of chaotic radar reach the above synchronization conditions.Under the condition of stable complete chaotic synchronization,the x and y chaotic polarization components are used as the chaotic radar detectionsignal,and the two targets(at two different positions)are respectively located.It is found that the performance of the ranging is stable and only has a slight instantaneous jitter,and its accuracy reaches the order of millimeter.And the SNR of the two polarization components is high and the real-time stability is good,even the measured target is at arbitrary positions,the relative error of the target range is very small,less than 2.7%,Which can be found in chapter 5.